Fixing a cowboy job roof gone wrong... and saving money!

[cdbe]

Those joists seem to be considerably undersized and at extremely large centres, I'd remedy that before going straight to the epdm. If the OSB is in poor condition but structurally sound overlay it with some 9mm. Your decorator friends will have the epdm down in half an hour, it's like wallpapering on the flat. Any temporary fix (other that a bucket underneath) is throwing good money after bad.

 

[Stonehouse2022]

Those joists seem to be considerably undersized and at extremely large centres, I'd remedy that before going straight to the epdm. If the OSB is in poor condition but structurally sound overlay it with some 9mm. Your decorator friends will have the epdm down in half an hour, it's like wallpapering on the flat. Any temporary fix (other that a bucket underneath) is throwing good money after bad.

Hi, thanks your input.

Why do you think the joists are undersized? They could be, but I was told they are the right size but perhaps not enough of them, then again another builder said there is adequate spacing between joists.

A builder did walk around on the top of the roof fine.

I'm deciding now whether to strip the felt, replace damaged OSB then put down EPDM... or just temp cover the whole roof with layers of DPM/TARP and batten down which two individuals say would last 2 years if done properly.

 

[Notch7]

Thank you for the suggestion, so the roof is 7.5 by 4.5 metre.


How am I rolling out the 4 x 25 metre dpm? 4 metre DPM roll going down length way across the 7.5 metre stretch? And then overlap the lengths and leave overhang?

Lay the DPM 90 deg to the fall

 

[cdbe]

You probably need something in the region of 8x2 at 600 centres for a 4m clear span.

My neighbour temporarily repaired his roof in a similar manner about 5-6 years ago, he's certainly had his money's worth out of some bricks and a sheet of polythene, makes you wonder why people bother with proper roof coverings.

 

[Stonehouse2022]

Hi guys,

thank you all for your responses.

i got the temporary cover on today and battened down nice and tight.

should last a while for now, DPM was great suggestion 300mu is solid stuff.

And then a whole new roof is needed with insulation.

The current fall angle is not enough needs to be 10 to 1.

The osb needs replacing with plywood.

so ill save up

 

[Notch7]

Hi guys,

thank you all for your responses.

i got the temporary cover on today and battened down nice and tight.

should last a while for now, DPM was great suggestion 300mu is solid stuff.

And then a whole new roof is needed with insulation.

The current fall angle is not enough needs to be 10 to 1.

The osb needs replacing with plywood.

so ill save upView attachment 234958

That's a nice neat job, well secured around the edges.

The angle of a flat roof is 1:40 for felt and slightly less for EPDM - providing the joists are strong enough and don't bow

 

[datarebal]

The Dpm will crack up in the UV.
I've some pictures some where of a flat roof covered Dpm after a lead theft . Less than 3 months it was falling apart